The ScienceAlert article “Sea Level Rise Is Accelerating, And We Now Know The Biggest Reason Why” claims that sea-level rise is not only accelerating but that scientists have now “closed the budget” and identified ocean thermal expansion as the dominant driver. This is false. Direct, long-term tide gauge measurements around the world do not show the dramatic acceleration implied in the satellite-based narrative.
The distinction between satellite altimetry and tide gauges is critical. Satellite measurements of global mean sea level began in 1993. That record spans about 30 years and involves multiple satellite missions stitched together over time. Each transition between satellites requires calibration adjustments. Even small offsets can introduce artificial curvature into the record, creating the appearance of acceleration.
By contrast, tide gauges measure sea level directly at specific coastal locations, in many cases for more than a century. For example, in Figure 1 below, the Battery tide gauge in New York City has operated since 1856. It shows a steady rise of about 2.8 to 3.0 millimeters per year, with no statistically significant acceleration over more than 160 years.
Many other long-term gauges around the world display similarly linear trends.
This matters because tide gauges measure what actually affects people; sea level at the coast. Satellite altimetry measures global averages across the open ocean. When the two datasets diverge in character, the longer, directly observed tide gauge record deserves greater weight.
The pattern in the Pacific Ocean known as El Niño causes sea level rise by changes in prevailing winds piling up water in the eastern Pacific Ocean, seen in Figure 2 below.
That bulge of water makes it into the global satellite sea level record but does not reflect what happens on coastlines.
The article leans heavily on the “global mean sea level budget” concept and emphasizes acceleration from 2005 to 2023. It should be pointed out that “budgets” are a human creation and that nature pays no attention to such things. But this budget conclusion depends primarily on the satellite era, which is short and subject to calibration uncertainties. When evaluating acceleration, the window of time chosen can dramatically influence the result. Starting in 1993, near the beginning of a strong El Niño cycle, naturally increases the likelihood of seeing curvature in the trend.
The Climate at a Glance sea level analysis shows that sea-level rise has been ongoing since the end of the Little Ice Age in the 1800s and remains modest and largely linear in long-term observational records. The rate today is not unprecedented compared to earlier 20th-century values.
The article also asserts that thermal expansion accounts for roughly 43 percent of recent rise. That may be true within the assumptions of their model budget closure. But again, this depends on reconciling satellite altimetry with Argo float temperature data and other modeled components. Budget closure is not the same thing as independent measurement confirmation. It is an internal accounting exercise constrained by the datasets selected.
Thermal expansion is a well-understood physical process. Warmer water occupies more volume. However, ocean heat content measurements prior to the early 2000s are sparse. The global Argo float network, which provides the most reliable subsurface temperature coverage, only became operational around 2005. That means the supposed acceleration tied to thermal expansion relies heavily on a short, modern dataset.
When you examine tide gauges in stable tectonic regions around the world, where the tide gauge is not affected by land rise or subsidence, you do not see a sudden doubling of the rate since 2005. What you see is continuity. Slow, steady rise.
The broader implication of the article is that accelerating sea-level rise will inevitably threaten millions of people in coming decades. That claim is entirely climate model driven. Projections are sensitive to assumptions about future warming, ice sheet dynamics, and feedbacks. Yet the historical record shows resilience and adaptability. Coastal engineering, improved drainage, land elevation adjustments, and infrastructure planning have long been part of managing coastal risk.
Sea level has been rising for more than a century. Cities such as Boston, Amsterdam, and Tokyo have adapted. The narrative that acceleration is newly discovered and unprecedented does not align with the long-term observational record. If acceleration were truly dramatic and recent, we would expect clear, unmistakable signals across century-long tide gauges. That signal is simply not there.
The difference between a stitched-together satellite record and continuous measurements should not be glossed over. Satellite data are valuable, but they are short indirect measurements and heavily calibration dependent. Tide gauges are long and direct measurements.
In the end, this article presents a technically sophisticated but selectively framed argument. It emphasizes acceleration derived from a short satellite era while underweighting the longer coastal measurement record. The public deserves to know that the evidence for dramatic new acceleration is far weaker in the observational data than the headlines suggest.
Sea level is rising; it has been for generations. The key question is whether it is accelerating in a way that justifies claims of looming crisis. The longest, most reliable measurements say no. ScienceAlert failed to look at all the science available, and in the process, created a biased and false article.
Anthony Watts is a senior fellow for environment and climate at The Heartland Institute. Watts has been in the weather business both in front of, and behind the camera as an on-air television meteorologist since 1978, and currently does daily radio forecasts. He has created weather graphics presentation systems for television, specialized weather instrumentation, as well as co-authored peer-reviewed papers on climate issues. He operates the most viewed website in the world on climate, the award-winning website wattsupwiththat.com.
Originally posted at ClimateREALISM
I get it–its a daily assault on the low information types.
Well it seems to me that the lowest ‘information type’ is this time the head post’s author en personne.
How is it possible to lack technical skills so much to write
” Sea Level ‘Acceleration’ Isn’t What the Measured Data Show ”
when you look only at linear trends?
Acceleration in data you can only detect when looking at a quadratic fit or when computing consecutive trends for the data.
Taking Battery (PSMSLid 12) as example:
Trends im mm/year for the absolute PSMSL data from various starts till 2025 (when eliminating the gauge’s vertical land movement, here subsidence, what reduces the trend in this case):
(When using raw data as in NOAA’s graphs, the trend for the sat era is even 4.87 ± 0.48 mm/year.)
If there was no acceleration, all trends would be identical, and the quadratic fit in the graph would be plain flat.
When considering the entire US East Coast (in a comaprison now using anomalies wrt the means of the sat era), the acceleration is even a lot higher:
Finally, a look at different global evaluations of PSMSL data (by Sönke Dangendorf & al, Thomas Frederikse & al, Grant Foster and myself, compared to NASA’s altimetry data:
Trends im mm/year for the common period of all five series (1993-2015):
Trends for 1993-2025:
One can see that except mine, these evaluations all show to be very near of tide gauge to sat data, if not even above it.
A steady rise in sea level is shown, That is accepted as correct by many. Length of day has not followed that path. LOD, length of day, has increased and decreased, it is much the same as a hundred years ago and it has decreased since the atomic clock was put in service measuring time in 1972, less leap seconds were added every decade since 1972 and none since 2016. Sea Levels are not increasing when Length of Day is not Increasing. Watch a spinning dancer put their arms in close and out. If sea level was rising for a hundred years Length of Day woulld have increased for a hundred years, if sea level rose since 1972, more and more leap seconds would have been needed to be added, less and less leap seconds have been added, sea levels have gone down since 1972 and have been steady since 2016.
SAN FRANCISCO / TIDES OF HISTORY / Presidio gauge has measured the bay’s rise and fall for 150 years
Over the years, the gauges also showed a gradual rise in the sea level — eight inches in 150 years. However, there was also a period of 38 years, ending in 1913, when the sea level declined.
The Presidio gauge @ur momisugly San Francisco gauge also measured other phenomena — such as the effect of the El Niño condition on water levels. The highest tide ever recorded was on Jan. 27, 1983, when the surface of the water at the Golden Gate reached 8.78 feet above mean sea level, or zero. The lowest tide was on Dec. 17, 1933, with minus 2.9 feet.
The 1983 high tide accompanied a downpour associated with the El Niño condition; the lowest accompanied a period of the exact opposite condition.
The normal tidal range is about 5.8 feet, more when the moon is full. The tide also affects the currents in the bay, which are strongest in the Golden Gate, and in the San Pablo and Carquinez straits.
http://www.sfgate.com/bayarea/article/SAN-FRANCISCO-TIDES-OF-HISTORY-Presidio-gauge-2745805.php
What does Presidio tell us about sea level from a gage situated on a vertical stable landplate?
From June 30, 1854 to Dec, 1932 the level was going down and before Dec. 17, 1933 there was NO rise.
Since Jan. 27, 1983, levels have all been lower, or no rise.
Total average gain is 8 inches total, while the twice daily Range is over 5 ft – 9 inches
An El Niño, i.e. when that 1 meter higher sea level by Japan sloshed back to the west & a lot of rain runoff caused the RECORD HIGHEST and not CO2.
With regards to the Battery
Take an Engineering Hydraulics class and should learn.
When the river running near by has more water or less of a channel to run thru, the surface will rise.
Run the same amount of water in a channel with narrowing width, the surface will rise. Compair the changed width of the Hudson River through Manhattan over the last 80 years.
As long as the planet is above a certain temperature, glaciers are going to generally melt. When below this temperature, they generally grow, as in the Little Ice Age.
Another way to tell that we are not warming is that the atmosphere has been contracting (happens when gases cool) such that the space station does not have to be boosted to higher orbit as often because the atmospheric drag is decreased. Yes, the space station is not really in space.
Chuck wrote: As long as the planet is above a certain temperature, glaciers are going to generally melt. When below this temperature, they generally grow, as in the Little Ice Age.
If you study ice core records, the ice accumulations are most when it is warmer and evaporation and snowfall are more possible, the ice accumulations are least when it is colder and evaporation and snowfall are less possible. More ice accumulations in warmest times causes ice to grow and spread and cause colder. Less ice accumulations in coldest times allows ice to deplete and thin and retreat and cause warmer times. It snows more in the Arctic region when the Arctic Ocean is not covered with sea ice. It snows less in the Arctic Region when the Arctic Ocean is covered with sea ice. Works the same in the South. Antarctica ice grows more when the Antarctic Oceans are warmer and Antartica loses ice when the Antarctic Oceans are colder. Evaporation and snowfall require warm thawed ocean water near cold places to deposit the snowfall.
Quite true. Most people do not appreciate that glaciers are truly rivers that move downstream very slowly. Ice is not a crystalline solid; it is amorphous meaning that it flows under the influence of gravity or any other source of pressure. When it snows on the glaciers headlands, flow increases, and vice versa just like liquid rivers do although very slowly.
FIFY. Amorphous means it doesn’t have a regular or crystalline structure. Glass is amorphous. Not even sure glacial ice is not crystalline, but not going to go look it up right now.
Sea level relative to land go up and down, as the crust moves up, down, and sideways.
Marine fossils are found at the top of Mount Everest, and oil formed from land flora is found at depths of several kilometers.
Oh well, in some places the land rises due to glacial rebound at around 15 mm/yr, or falls 300 mm/yr due to other causes. Rises or falls of 350 mm overnight due to seismic activity are not uncommon.
Of course the ignorant and gullible crowd who believe that adding CO2 to air makes thermometers hotter also believe that the ocean depths are heated by the sun, that the shapes of the ocean basins aren’t continuously changing, and that deep ocean currents at 180° to each other are due to surface winds (or climatological magic)!
Who would bother worrying about pronouncements from such obvious nutcases?
Lots of even more ignorant and gullible people, it would seem.
“Sea level relative to land go up and down, as the crust moves up, down, and sideways.”
A paper with a full set of sea level and land movement measurements is found here.
(PDF) Absolute and relative sea-level rise in the New York City area by measurements from tide gauges and satellite global positioning system
The actual real sea level rise at Battery is something like 0.7mm/year, with a very small acceleration.
That’s 8 microns. Best not use a meter rule to measure it, because the rule will expand or contract more than this for every °C change.
These climatologists are either exceptionally talented metrologists, or maybe occupy an alternate reality.
I get 0.32 mm/yr with acceleration of 0.012 mm/yr°
Source PSMSL & Microsoft Excel
“[Battery tide gauge] has operated since 1856. It shows a steady rise of about 2.8 to 3.0 millimeters per year, with no statistically significant acceleration over more than 160 years.”
Did anyone check that?
I calculated the trend from 1856 to Oct 2025 as 3.18 mm/year, with std error 0.03.
But the trend since 1999 is 6.15 mm/yr, with std error 0.46
The difference is 2.97 mm/yr, about six sigma (6x SE). Highly significant acceleration.
I stopped at Oct 2025 because the data since then is incomplete.
Part of an oscillation. Rate was higher in the mid 1950’s
Over the full period there is basically no acceleration.
Of course not (what would it mean?). The question is whether there is recent acceleration. AW says that the Battery proves that there isn’t, but the Battery in fact shows large and statistically significant acceleration since 1999.
There has been a recent upward leg of the oscillation.. the short period is totally meaningless when the whole data is full of oscillations..
Tide gauge at Battery went DOWN from 2010 to 2017.
The steep bit at the end coincides with the 2023/24/25 El Nino event.
You do know that the OLS mean on that graph is actually accelerating?
It is exhibiting a second derivative.
Look at the exponent !!
10 to the MINUS 6.
Meaninglessly small.
And so it should be – for the entire period of 130 odd years.
But what is it for the last 30 years (or 27 as Nick calculated)?
Atmos CO2 content did not really start to climb until post 1960 BTW…..
So you are tying CO2 to the heating of the oceans that cause global sea levels to rise?
Yes we know sea level acceleration is meaninglessly small.
Thanks for that.
And as I have already shown, the 30 year period ending in the mid 1950s has the same or slightly larger trend.. so was that caused by CO2.???
Your boat is sinking.. again !!
And why should CO2 have any affect on sea level rise at all.. what a ludicrous conjecture. !!
Nick:
Why did you pick 1999? Were there any other ~27yr periods in the record that had similar accelerations or was that the only one? My eyeball suggests multiple ups & downs.
And as Mr Watts suggests, there should be multiple stable tide gauges showing a similar finding.
“Why did you pick 1999?”..
Its called “cherry-picking” !.. It is what alarmists do.
The graph I posted above show 30 year linear trends (trailing)
Here is the 20 year trailing trends chart
Linear residuals also show no sign of any acceleration.
There is a definite dip between about 2013 to 2020, which is part of the cherry-picked period.
Also shows up in tide data from 2010-2017,
And here is the graph of 7 year trailing linear trends.
As you can see, trend is now DECREASING as part of a CYCLE.
OOPsy.. That graph above is actually the 8-year trailing linear trends. (95 months actually)
This one is the 7-year trailing trend graph (with pre-1900 not shown because of missing data)
Can anyone NOT see the oscillations !! 😉
And the fact that trend is now decreasing. !
Since 1999 means this century (26 yr).
But the key is statistical significance. That means there was (big) acceleration and it wasn’t due to chance.
I doubt that earlier accelerations were statistically significant. That means they could have been due to chance.
Cherry picking a short period at the end of very obvious oscillations… Is meaningless.
Cherry picking *any* start point of an oscillating signal can create *any* slope you want. Linear regression simply can’t identify an oscillating signal properly.
Ah. … and now a quote by you from a Monckton thread in 2022….
https://wattsupwiththat.com/2022/07/02/the-new-pause-lengthens-to-7-years-10-months/#comment-3548586
“When CO2 has gone up significantly over the past seven years but the temperature has not the so-called “climate scientists” need to start looking for why their models are giving the wrong answer. Their physics are wrong somewhere. Coupled with the prior pause there is no way the models can be correct.”
Forgive me …. but why does a 7 year trend in GMAT signify that
“(models) .. are giving the wrong answer.”
Yet now “Cherry picking *any* start point of an oscillating signal can create *any* slope you want. Linear regression simply can’t identify an oscillating signal properly.”
There’s a word beginning with “H” that rightly describes the above.
Ah, the exact method that a certain Lord used to calculate his “pauses”.
Thanks for confirming that they were “meaningless”
I seem to remember that WUWtians thought them very meaningful!
You obviously don’t understand Lord Monckton’s methodology, which applies only to finding longest zero trend.
Same as you don’t seem to understand negative exponents.
Why do you think 1999 is special, then?
You cant just choose a date and claim statistical significance since that date without an underlying physical cause. Its not obviously “CO2 driven global warming” because that’s been happening for much longer.
I mean one obvious choice is the extreme ENSO event that you’re starting your measurement from…
The WUWT claim is that lack of acceleration disproves the satellite finding of acceleration. But there is a new high and significant trend over that period. So it certainly doesn’t disprove. Whether it proves anything is another matter.
In fact there is nothing special about 1999. Nearby dates give similar results. For example starting after 1990 gives a slightly lower trend at 4.93 mm/yr. But the SE is less, being a longer period, at 0.28. So even more than six sigma. Starting at 2010 gives 5.55 mm/yr, but a higher SE of 1, so not significant.
I must say this is a typical WUWT sequence. The claim is that scientists are wrong, because the Battery has no significant acceleration. Nobody checks. I show it has. So then the endless – why did you choose 1999 etc. It wouldn’t matter what I chose. But no-one is curious about the validity of the original unquantified claim.
Looking at bnice’s graph, similar increases happened earlier last century. Unless they can be explained then whatever physical changes that happened in the 90’s cant be confidently attributed to CO2
Well I am but I can also see that over time sea level rise rate is all over the shop. I am particularly sceptical of claims of sea level rise that is exponentially increasing because its not supported by the energy conserving GCMs. Exponential increases only come from extrapolation models.
For all their failings at least GCMs wont allow energy to enter the system exponentially.
“whatever physical changes that happened in the 90’s cant be confidently attributed to CO2″
The question here isn’t attribution. It is whether the satellite observations should be disbelieved because of tide gauges, and specifically NV Battery. But Battery is showing the same acceleration. Maybe there were other accelerations in the past, but we don’t know whether satellites would have said the same.
Well I agree that your analysis for that date range is probably correct without confirming it myself. But the claim was
So it does mention long term. And
And I’d be surprised if your calculation was significant over the long term. You need to invoke a change point and we’re back to where we were with attribution.
No-one is claiming long term acceleation. The claim here is that oceans are rising in response to warming (however caused), and the acceleration is on that time scale. And that is why it is relevant that the Battery tide gauge is also accelerating on that time scale – ie recent decades.
Ok, so ignoring Anthony’s claims that we should look at the bigger picture, then the claim is accelerating warming of the oceans from accelerated heating.
From the reference in the paper Satellite and Ocean Data Reveal Marked Increase in Earth’s Heating Rate
We see the earths heating rate is not accelerating so the sea level increases cant be accelerating either. Its linearly increasing.
“We see the earths heating rate is not accelerating so”
Your graph does not show the Earth’s heating rate. But the heating does not need to be accelerating. It just needs to be getting warmer, as it has been.
But again, this is all about cause. The question to be resolved here is just – is sea level rise accelerating? Arguments about cause come later.
Energy uptake in the ocean is equivalent to heating. The graph even says its heat uptake.
To answer whether the sea level rise is accelerating, its cause needs to be understood and explained otherwise sea level rise increases are just variations.
Just a side note, not for or against you; You are one of the few that will actually respond to comments of those who don’t agree with you.
Buy that I mean, most just reply with a declaration, “You’re wrong!”.
“Direct, long-term tide gauge measurements around the world do not show the dramatic acceleration implied in the satellite-based narrative.”
So are you implying that satellite data is wrong?
You do know that there is a tad more ocean that just that lapping against coasts?
https://sealevel.nasa.gov/faq/9/are-sea-levels-rising-the-same-all-over-the-world-as-if-were-filling-a-giant-bathtub/
“Ocean Dynamics and Gravity: Ocean levels do not rise uniformly like water in a bathtub. Factors like wind, currents, changes in Earth’s gravity field, and regional water temperatures cause sea levels to rise faster in some areas and drop in others. Satellites capture these shifting global patterns, whereas a tide gauge only records a single point.
What is incorrect is the claimed accuracy. The claimed measurement uncertainty is so so far below the resolution available it simply can not be correct.
The height of the center of the ocean has no meaning to what the sea level rise is on the coasts.
A global sea level rise has no more meaning than a global average temperature.
No, I’m saying analysis that finds acceleration from changing slopes over short time periods is wrong.
When the analysis shows accelerated TOA radiative imbalance acceleration from understood physical factors that cause the acceleration, then sea level rise acceleration will follow.
Nick’s calculation was less than 0.25 mm/yr long term greater than stated on the graph, as if this is somehow statistically significant and he has stumbled upon some dispositive error proving him right and everyone else wrong.
No, Nick. That isn’t the question. That is only your question. no one else cares about your framing.
It is the question! The headline here reads:
“Wrong, ScienceAlert: Sea Level ‘Acceleration’ Isn’t What the Measured Data Show”
So the question is, what does the measured data show? And the answer is, acceleration!
When the answer is derived as a mathematical observation, then it doesn’t have underlying physics supporting it.
NO. It shows part of an oscillation.
The data shows a short period with a trend similar to the 30 year period leading up to the mid 1950s.
And more recent data shows that trend diminishing.
Here is the data to back up that oscillation.
The 7-year trailing trend shows the oscillations very clearly.
Since 2023, the trend is decreasing… that is NOT a sign of acceleration.
Uh oh! Harold Pierce will be upset! You graph DIDN’T expand when clicked, it got smaller!! Oh noes!
My fault, I posted it from a different computer, by copying from elsewhere in the topic… and didn’t check the file size 🙂
You simply showed there was a small increase in trend over a small period of time. That is NOT how statistical significance is determined.
Your claim that this technique is appropriate for determining an increase in trend discredits your and other climate warmists claim that “bias” correction and homogenization is needed to create long temperature records. Your assertion here would lead one to believe that a sequence of short 20 – 30 year trends would better describe what is occurring with temperatures. For example, short temperature trends would show up, down, and sideways trends while CO2 would show a constant rise. That would indicate no cause and effect.
Measurement uncertainty does mean something. Several years ago when I dug into Jason satellites, I was amazed to find out that the satellites could vary in height above the earth by feet because of the vagaries of gravity.
I was also dismayed that the uncertainty this causes was waived away by dividing the total uncertainty by the “√observations” to determine the standard error of the mean and claim it as the measurement uncertainty. This statistical technique is only appropriate in metrology to determine the measurement uncertainty for a single unique measurand when multiple samples, each of size “n”, are made on that single thing. In general, single measurement uncertainty is the standard deviation determined from multiple single observations. As a result, satellite sea level measurement uncertainty is far beyond what is clamed as the accuracy of the measurements.
Lastly, a single global average sea level is as meaningless as a global average temperature. The oceans of the earth should be broken up into smaller and smaller regions. The Arctic Ocean is not the same as the Indian Ocean as the North Pacific, etc. It is the same old story, let’s average everything together to get a long record and so we have a reason to minimize measurement uncertainty.
“You simply showed there was a small increase in trend over a small period of time. That is NOT how statistical significance is determined.”
Not “small” – 27 years. The period considered significant for climate is just 3 years longer.
Oh, and a certain Lord calculated his pauses at less than that – the longest being 18 years and 8 months.
I seem to remember he was cheered on on here and was very much thought to be correct.
Now why would that be considering your quote?
Your assertion matches what concensus climate science says but that doesn’t make it correct. A cyclic process in climate may far exceed 30 years making any conclusion about what occurs in 30 year subject to a large uncertainty. Unless you can show that there is no cycle involved, then any conclusion about a short term change is premature and likely wrong.
How about answering the main thrust of my post? ….
Why is it OK from Monckton to do it for much less time than the notional 30 years … in fact just 18 years 8 months for his longest abortive “pause”?
And not OK for Nick Stokes?
Surely it can’t be because Monckton is/was “on your side”,
and Nick isn’t?
Nice, how one can do a complete about-face just depending on whether your world-view is being attacked or being supported.
I’ve said elsewhere on this thread that that constitutes the expression of a certain noun that begins with a “H”.
You don’t really deserve an answer but I will give you something.
Monckton had a purpose to prove that CO2 was not the “control knob” that controlled temperature. The longer a pause lasts while CO2 is climbing the less evidence that CO2 is the control knob.
Now you tell us what underlying variable exists that this acceleration proves.
The 30 year period ending in mid 1950 had the same or slightly larger trend.
Well yes but when Monkton stated the pause length, he wasn’t claiming the end of warming, he was claiming no statistical warming for the pause length.
By comparison when you claim acceleration for some recent period, you’re not claiming its a statistical anomaly in the period, you’re actually claiming warming is accelerating.
What you dont understand is that you’re claiming a fit is predictive physical reality.
100%
It is for Nick. He’s a mathematician. He’s good with numbers, not so good with significance or relevance.
A monk, Dionysius Exiguus, calculated the starting point of our calender in the year 525 under the direction of Pope St. John I. That is why, and only why, the 21st century started 26 years ago. Why you think that has some scientific merit is a mystery.
You are using the same technique that you and others have criticized Monckton for. That is, working backwards to find a trend that matches your preconceived idea of what is occurring. Don’t be a hypocrite.
And, it should be said, the same technique that WUWTians were perfectly happy to go along with in Monckton’s case.
But not with Nick.
Seems to me that that smacks of a certain something.
“Since 1999 means this century (26 yr). But the key is statistical significance.” Probably millennium. I suspect that it is statistically significant that a scientific paper citation now would be 2000+.
There is no such thing as “chance.” “Chance” does not exist. Therefore, nothing is “due to chance.”
He picked 1999 because that starting point shows that the rise rate has increased. Had he picked 1990 or some earlier date, it wouldn’t. That is what Nick does, always.
As I showed above, 1990 gives a slightly lower uptrend, but even higher significance.
One thing for sure is that nobody else is trying to actually quantify the acceleration, or lack thereof.
Another “do as I say not as I do” WUWTian.
Now tell me what is it that a certain Lord did in calculating his “pauses?
I made an error for the trend since 1856, caused by not allowing for the gap in data in 19th century. The correct numbers are 2.95 mm/yr (not 3.18) with SE still 0.03. It makes no difference to the conclusion that there is a very significantly higher trend since 1999. That recent calc is still correct, because there are no gaps.
SE is an improper statement of measurement uncertainty. You are not measuring a single measurand multiple times. At best you are determining the property of a non-homogeneous phenomena. The appropriate measurement uncertainty is the standard deviation between observations. It is know as the reproducibility uncertainty due to changes in the measurand.
Your recent calc may be still correct, but it is still irrelevant cherrypicking.
Sea Levels are difficult to measure all over the world, sea levels are hard to average to get any answer, the errors in measurement and averaging are orders of magnitude more than the published sea level rise. Sea Level rise influences inertia of the crust of the earth, ice near the spin axis vs water around the equator. Length of day is similar to a hundred years ago and is less than in 1972 when the atomic clocks were put in service to measure time accurately. Less leap seconds were added every decade since 1972. That means sea level has decreased since 1972. A rising sea level would require more and more leap seconds every year, the opposite has happened.
Here is a graph of annual averages of measured sea level at the Battery, in mm, with less noise, so you can see the change. I have marked the trend line from 1856, and the one starting 2000.
OMG. What a massive load of cherries you have picked. !!
Relying on two points at the peak of an El Nino event.
Really?? I got rough estimate of 2.94 mm/yr. You’re seriously going to nitpick over 0.25 mm/yr (or lesss)? And your comment about the trend since 1999 is nothing but irrelevant cherrypicking.
I have posted on this issue here several times before over the years (with lots of referenced footnotes). AW is correct, and for more reasons than he modestly gives in this post.
“Official order of magnitude metric nonsense.”
But the SEM is +/- 0.03cm, in the HUNDREDTHS digit. (hint: all the SEM tells you is how precisely you have located the mean of a population, it does *NOT* tell you how accurate that so precisely located mean is).
My guess is that in order to calculate the SEM, Nick also assumed the standard deviation of the sample data, and the data *IS* a single sample of the global population of sea level, is the same as the standard deviation of the population – with no justification given for making such an assumption.
If I remember correctly a sample size of 1 gives a built-in measurement uncertainty of about 30%. Since we don’t have multiple measurement systems making multiple samples and the satellite network doesn’t make multiple independent measurements at each point thus creating separate, repeatable samples, the data set *is* a single sample.
And, as you point out, measurement uncertainty cannot be less than the resolution of the measurement device where the requirement of repeatability of measurements is not met. Resolution thus becomes a floor for the measurement uncertainty. Additional impacts from environmental conditions, instrument drift, etc add to the uncertainty.
A claim of a measurement uncertainty of +/- 0.03cm is just garbage. It just highlights the statistical malpractice typically displayed by climate science of assuming that all measurement uncertainty is random, Gaussian, and cancels.
+100
That’s not necessarily true. If there is enough noise in the measurements to give a random variation of at least one significant bit, AND there is no long term drift in calibration, multiple measurements can improve resolution. This is very often done with A/D converters. In this case case, resolution improves with the square root of the number of samples.
With satellite altimetry, I would wonder about long term drift in calibration.
You are mixing two different measurement concepts, precision and resolution.
Precision is the variation found when measuring the same thing under repeatable conditions.
Resolution is the ability to resolve a given increment in the value of a measurand. Resolution is a property of the instrument and sets the minimum increment that can be distinguished in a single reading.
Here is an example.
I have a digital voltmeter that has one decimal digit and I use it to measure a voltage reference that has a value of 1.02 volts. The device will appear very precise since it will always display 1.0 V. However, the resolution isn’t available to measure values in the hundredths digit. Depending on the electronics, the best (not including other uncertainty categories) one can say is that the value of the uncertainty is ±0.05 V. As an interval, one would say the measurement may be anywhere within (0.95 to 1.05) which obviously encompasses 1.02 V.
Be careful of thinking you can use an estimated extra digit to achieve a better resolution. That estimated digit is where uncertainty starts. In other words, it becomes a part of the ± uncertainty.
I think it was one of the regulars here that did the calcs for this chart.
Shows just how little acceleration there is at tide charts around the world.
test
I’m new to posting images. Your retread of this chart is a good stab at answering the wrong question. Instead of merely looking at all of the extant data, you should be comparing pre and post ACC data. I used 1980 as a split date, and YMMD. I:
Jumping to the end, the average acceleration for all of the data for the ~65 stations was for ~0.011 mm*yr^-2 – just what Steve Case got. But pre 1980, that same set of stations averaged ~-0.013 mm*yr^-2, a tiny deceleration. For 1980-present however, same set of stations, average acceleration increased by nearly a factor of 8, to ~0.086mm*yr^-2. This evaluation is 2-3 months old – newer than yours.
I didn’t calculate the chance that, given the spreads, one of the 3 evaluations is actually higher than another one with a larger expected value, because I can see by inspection that my laptop would flip and burn from the effort.
Deceleration then acceleration.
Its called an OSCILLATION. !!
And has been happening for ages.
You don’t identify oscillation periods using OLS. Why does climate science never do a Fourier analysis on the data to try and identify oscillation periods? Of course, Nyquist would require an observation period long enough to identify low-frequency oscillations, perhaps hundreds of years worth of good data (like in your graph)?
Thank you Tim. Nobody has demonstrated oscillatory behavior in Steve Cases’s choice of 65 stations. What HAS been demonstrated is that, the money evaluation, pre and post ACC evaluation, along with validation of Steve’s evaluation, shows a big increase in overall acceleration, post 1980. Is it just the latest of several acceleration “oscillations” that happen to be positive? No idea….
You mean no one has ever investigated it? Can YOU post a link where someone has obtained a data set that shows no oscillation period longer than 30 years?
That’s exactly what I mean, AFAIK. And no, I can’t post such a data set. However, above ground, “prove me wrong” don’t get it. It’s up to the person making the claim, to back it up. As you said, bnice did not.
How do you prove a negative? If something doesn’t exist how do you prove it doesn’t exist? How do I prove no studies analyzing cycle periods exist if they don’t exist? On the other hand, your claim that they do exist can be proven bu pointing to one that exists,
“How do you prove a negative?”
The supposition under eval here is that there is oscillatory behavior in the combined response of the 65 stations under discussion. To underlie my valid assertion that acceleration takes off after 1980, for that group, you would have to find that that the post 1980 behavior is just the latest.
“On the other hand, your claim that they do exist can be proven bu pointing to one that exists,”
Read for comprehension. I never made this claim.
You are kidding, right?
The study period has to be long enough to capture low frequency oscillation. You are postulating that the study period here is long enough yet you can’t point to any studies showing that. It’s an assumption you are making with no actual justification. How do you KNOW this is a unique situation?
[I let the mosquito buzz around Nick a bit earlier but you’ve used it up.~ctm]
Here is the graph of 7 year trailing linear trends.
Tell us there isn’t an oscillation.
One station. Now, do the 65,
And BTW, the main attribute of your chart is the post 1980, irregularly oscillatory increasing increase. There’s a name for it – give me a sec.
You are grasping at metal straws in a sinking boat !
You’re lucky you can post images. I paid for a more expensive subscription to help Anthony a bit….and found I no longer had the image posting option. If anyone knows how to fix it, post pls….
Not me. My only suggestion is to make sure that you’re posting image type files. Many here post many such files, and I’m sure can help.
I have trouble placing the image in the post but if you just select the image and not try to place it anywhere, it seems to work albeit at the end of the post.
And from a recent paper….
And another paper from Japan..
From here
“The absolute and relative rates of rise of the sea level are computed for the New York City area by coupling global positioning system records of the position of fixed domes nearby tide gauges, with the tide gauges’ records. Two tide gauges are considered, one long-term trend, more reliable, The Battery, in lower Manhattan, and one shorter, less reliable, Sandy Hook, in New Jersey. The relative rates of rise of the sea level are +2.851 and +4.076 mm/yr. The subsidence rates are -2.151 and -3.076 mm/yr. The absolute rates of rise of the sea level are +0.7 and +1.0 mm/yr. The relative sea-level acceleration, reliable only in The Battery, is about +0.008 mm/yr².”
Very SCARY… not… so…. DON’T PANIC !!
Here’s a helpful chart showing the rise in sea levels since the end of the last ice age. The Statue of Liberty provides a useful size reference. It is interesting to note that around 6,000 years ago, the rate of sea level rise slowed drastically. Feel free to use this chart, and visit http://www.the-world-of-co2.com/co2 for more interesting charts on CO₂ and climate change.
Anthony,
You show a New York graph with about 3 mm per year sea level rise since about 1860.
What is the accepted cause of this change?
If it is accepted, why is it being contested?
Is the accepted cause (if any) in doubt beyond the customary way that science progresses, refinement of the conventional wisdom?
Geoff S
The Battery sea level gauge on the southern tip of Manhattan also has a GPS elevation gauge operating since 2012. This elevation gauge data is provided on the PSMSL.org sea level website but not on the NOAA sea level website.
The GPS data in the “other information” button on the PSMSL.org page for The Battery shows that this location is subsiding at a rate of about 2 mm/yr making the absolute sea level increase rate at The Battery about 1 mm/yr. There is no inflection in The Battery sea level gauge data in or near 2012 which strongly suggests that the subsidence is a geologic feature which has been going on since and likely before the tide gauge was installed in 1856. The absolute sea level increase at The Battery is consistent with that elsewhere which has been determined to be 1-2 mm/yr where GPS data is available.
You also said “That bulge of water makes it into the global satellite sea level record but does not reflect what happens on coastlines.” Wind induced increases in sea level are noted at locations leeward of prevailing winds. Since winds do not alter the overall amount of water in the seas, then sea level at the opposite (windward) locations must decline. Your chart shows this.
Easy solution to the fear of rising oceans that will drive climate nuts crazy. Nuclear-powered desalination plants around the world, especially in drought common locations.
I don’t belief that the amount of ground water used is matched by rain fall replenishment. We know that some of the recorded sea level rise recorded in some locations is tied to ground water depletion. We should be working on drawing water from the sea to overcome and exceed the outflow to replenish the aquifers to a sustainable level.
If we cut all the wasted money spent on people studying a “solved problem” and the wasted government funds supporting climate insanity, it would be a good start.
ARGO is much better than what was available before, but even it is far, far short of what would be needed to accurately measure the energy content of the entire ocean.
We had no idea before We have a faint glimmer now.
Is it land subsidence or sea level rise?
https://www.science.org/content/article/satellite-maps-sinking-coastlines-come-under-scrutiny
That’s why we have satellite data:….
https://sealevel.nasa.gov/faq/9/are-sea-levels-rising-the-same-all-over-the-world-as-if-were-filling-a-giant-bathtub/
Satellite don’t have the accuracy to measure a moving sea surface.
(rather like the Met-Office temperatures.. accuracy is a splatter-gun)
What matters is the tide gauges.
A full analysis was done
The actual sea level rise at Battery is 0.7mm/year
https://wattsupwiththat.com/2026/06/12/wrong-sciencealert-sea-level-acceleration-isnt-what-the-measured-data-show/#comment-4206031
A used car salesman tells you that this car can accelerate 0-60 mph in 6 sec.!
You buy it. You “put the pedal to the metal”.
Then you find out he misspelled and mis-abreviated “sec”. He meant “centuries”, not “senturies”.
(Correct me if I’m wrong, didn’t some “project” that Miami and parts of NYC by now should already be underwater?)
Not wrong. Obama and Hanson, respectively. Both anecdotes related and illustrated (with footnotes) in an essay in my ebook ‘Blowing Smoke—Essays on energy and climate’.
I should actually read your book sometime.
But it sounds like you’ll only be filling in the details us “Mr. Laymans” didn’t already … I was going to say “know”. But I think “didn’t already smell” would be more accurate. 😎
Clintons. Obama. Al Goricle, … ,if I went further, the smell might get me banned! (Even on WUWT!) 😎
to remember: satellites get drift recalibrated via tidal gage reference. I suggest to view Dave Burton’s website. He is showing detailed 2016 NOAA tidal gage data of 375 worldwide spread of tidal gages. http://www.sealevel.info/MSL_global_trendtable5_J.html. Projected around 6 inches linear increase per century, plus around 2 inches (0.0524 mm/yr^2) due to acceleration. So, nothing to lose sleep over.
What is the accuracy of the satellite altimeter readings of ocean levels?
I recall (perhaps wrongly) that it was in terms of 1 or more centimeters.
How can a measurement that resolves to centimeters make an accurate reading of millimeters?
Nailed it. You can’t.
Climate science believes it’s cloudy crystal ball is 100% accurate. They can know the Great Unknown.
It can not be done. Beyond the resolution is estimation. In measurements, that is why there is a quantification called measurement uncertainty. Estimates begin at the point where uncertainty starts.
Sparta Nova 4
You are confusing measurements with trends.
When looking at
you see the difference between monthly measurement deviations.
I see in thre data that these measurement deviations from month to month vary between -32 and +24 cm; you can easily imagine how the daily variations can be.
But nevertheless, the linear trend from 1900 till 2025 for the raw NY Battery time series is 3.2 mm/year.
With satellite measurements, the deviations on the high seas can be significantly larger than in the basins of tide gauge stations, yet the annual trend here, too, is around 3 mm/year.